Pregnancy Symptoms Vs Period

General Health and Preventive Care  /  Blog

Pregnancy Symptoms Vs Period

Courtney Bennett

Written by Courtney Bennett

Courtney Bennett

Courtney Bennett

Dr. Courtney Bennett aims to simplify the complexities of modern medicine, enabling readers to make informed choices about their health. Her interests include reading, camping, hiking, painting, and photography.

May 11, 2018 / Read Time 7 minutes

Learn the Different Symptoms Between Pregnancy and Period

Trying to conceive a baby can be an exciting, frustrating, and mystifying experience.

Conversely, having a pregnancy scare when you are not actively trying to conceive can induce a lot of anxiety and worry.

Since period symptoms and pregnancy symptoms before a missed period can be so similar, it can be difficult to distinguish between the two.

Many women wonder about the difference between pregnancy symptoms vs period symptoms, and exactly how early they can tell if they have become pregnant.

While a late or missed period is the first indicator for many women, depending on where you are in your cycle, you may notice symptoms of pregnancy before a missed period.

Learn some key differences and indicators that can signal early pregnancy.

The Menstrual Cycle

The menstrual cycle is counted from the first day of bleeding in a given month, through ovulation, to the first day of bleeding in the next month.

The cycles can last anywhere from 21-45 days when a woman first begins menstruating, but will generally shorten to 21-34 days after a couple of years. The average cycle time is 28 days.

Women often use birth control to alter their period.

Around 14 days into a woman’s cycle, ovulation begins.

Ovulation occurs when an egg, or ova, is released from one of the ovaries. Each time a woman ovulates, the most mature egg is released. This egg travels down one of the fallopian tubes toward the uterus. Before the egg reaches the uterus, the uterine lining (also known as the endometrium) thickens with blood and spongy tissue in order to prepare for the potential attachment of a fertilized egg.

In a typical period, when the egg goes unfertilized, your body releases hormones that begin menstruation. During menstruation, prostaglandin causes the uterine muscles to contract and the extra blood and tissue is shed and discharged through the vagina. In contrast, when the egg is fertilized by a sperm cell while traveling down the fallopian tube, its cells will begin dividing. Once the fertilized egg (zygote) reaches the uterus, it may attach to the thickened uterine wall. This is referred to as implantation and marks the beginning of a pregnancy – this typically occurs 6 – 12 days after ovulation. After implantation, the zygote is referred to as a blastocyst.

However, it is important to note that roughly half of all fertilized eggs do not implant and are discharged during your period. If the blastocyst successfully attaches and begins developing the amniotic sac, it is then referred to as an embryo.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Period Symptoms

The amount of blood and tissue that will be shed during menstruation varies from woman to woman, but it may be less than you’d think – the average amount is equivalent to about two tablespoons.

Period blood can be pink, red, or brown and at times will have clumps of tissue in it.

Menstruation generally occurs for 2 – 7 days, but will typically be lighter and shorter when you first start having your period.

Menstruation will take place from the time a girl hits puberty (typically between the ages of 11 and 14) all the way through menopause (typically around age 50). In addition to the discharge of blood through the vagina, common period symptoms include:

  • Abdominal or pelvic cramps

  • Water retention (bloating)

  • Headache and fatigue

  • Breast tenderness

  • Mood swings and irritability

  • Pimples / acne outbreaks

  • Food cravings

The severity of these symptoms are different for every woman, and often fluctuate throughout a woman’s life. Symptoms may even vary from one cycle to the next.

Many women find it helpful to track their menstrual cycle and period symptoms in order to identify a pattern. This is also useful if you are trying to conceive because you can identify the times of the month that you will be ovulating, and therefore have the highest probability of conception.

Early Pregnancy Symptoms

Many early pregnancy symptoms are easy to miss because they mimic period symptoms rather closely. For this reason, it is important to note that experiencing some of these symptoms does not necessarily indicate a pregnancy.

However, if you suspect pregnancy is a possibility, it is always better to be safe than sorry, and to confirm whether you are pregnant before engaging in any activities that may be harmful to a developing fetus.

Early pregnancy symptoms before missed period flows include:

  • Implantation bleeding (spotting) and cramps. These symptoms occur as the zygote attaches to the uterine wall. When implantation occurs, blood vessels in the uterine wall are often ruptured, causing the bleeding. While this can feel similar to the start of a woman’s period, the flow tends to be much lighter. Additionally, the blood tends to vary in color from a woman’s typical cycle, typically appearing more pink or dark brown, almost rust colored.

  • Nausea and vomiting. While morning sickness tends not to rear its ugly head until a month or two into a pregnancy, some women may experience these symptoms shortly after implantation. Morning sickness may last throughout the duration of the pregnancy, or it may dissipate after the first trimester.

  • Vaginal discharge. Aside from bleeding, some women will notice a white, milky discharge. This is caused by the increased cell production and thickening of the lining in the uterus, and can last throughout the pregnancy.

  • Tiredness and fatigue. This is a very common early pregnancy symptom because the levels of progesterone in your blood spikes and can cause sleepiness. Progesterone helps maintain the pregnancy, and contributes to the growth of the breast’s milk-producing glands. These symptoms can be noticed as early as one week after conception.

  • Breast tenderness. Similar to period symptoms, the hormonal changes associated with pregnancy can make the breasts tender and painful.

  • Frequent urination. This is an interesting symptom that is caused by the increase blood circulating in a pregnant woman’s body. Since it is the kidneys’ job to process the blood, the extra fluid byproducts end up in your bladder. This will continue throughout the pregnancy, and likely worsen in the later trimesters as the growing baby can put pressure directly on the bladder.

  • Elevated body temperature. An elevated core body temperature is another side effect of the increased blood flow during pregnancy. The body’s metabolism is increased, increasing blood flow to the skin, thereby raising the body’s temperature.

  • Food cravings or aversions. Both developing food cravings and suddenly noticing a strong distaste for your favorite foods can happen early in your pregnancy. While food cravings are sometimes experienced during menstruation, food aversions are very uncommon.

The American Pregnancy Association conducted a poll on the early pregnancy indicators that women noticed. The results showed that:

  • 29% of women reported a missed period being the first sign

  • 25% of women reported nausea or morning sickness

  • 17% of women reported a change in their breasts (tenderness, size)

If you think you may be pregnant, you should take a pregnancy test and consult your primary care physician.

  1. 1

    Book on our free mobile app or website.

    Our doctors operate in all 50 states and same day appointments are available every 15 minutes.

  2. 2

    See a doctor, get treatment and a prescription at your local pharmacy.

  3. 3

    Use your health insurance just like you normally would to see your doctor.

Differences between Period vs. Pregnancy Symptoms

The main difference between period and pregnancy symptoms is the hormones that cause them.

While period symptoms are caused by fluctuating levels of progesterone and estrogen, pregnancy symptoms are caused by the hormone human chorionic gonadotropin (hCG).

HCG hormone stimulates the ovaries to continue producing estrogen and progesterone, and prevents the release of any additional eggs. It first begins to show in a woman’s blood and urine a few days after implantation. A woman will not have a positive pregnancy test before this hormone is present in high enough levels.

The hCG levels in urine are more variable and almost always less concentrated, which is why a blood test can detect pregnancy earlier and with more accuracy.

In addition, frequent urination and an elevated body temperature are unlikely to accompany menstruation.

Both of these symptoms are caused by the increased blood flow as a pregnant woman’s body adapts to support the developing fetus. Some women experience nausea during their period, more often during PMS, but vomiting is rare – especially if she does not have Premenstrual Dysphoric Disorder (PMDD) or another type of reproductive disorder.

Similarly, food cravings can often accompany your period, but food aversions during menstruation occur seldom, if ever. Suddenly developing a strong aversion to one of your favorite foods may be a hint that you are pregnant.

While bleeding can be caused by both menstruation and implantation, implantation bleeding will differ in that it generally occurs in small amounts (spotting), while the first few days of a woman’s period are generally the heaviest.

If you are expecting your period but instead only lightly bleed for a few days, you may be pregnant.

Finally, women may notice that their regular vaginal discharge changes to the milky white consistency that is caused by the changes the uterus is undergoing – namely increased cell production.

When to Contact Your Doctor

If you think you may be pregnant, you should consult with your primary care physician as soon as possible. It is crucial to begin prenatal care as soon as possible to ensure the health of your baby.

Over the counter pregnancy tests tend to be fairly accurate if they are not taken too early, but the only way to be completely sure is to complete a blood test that looks for the presence of hCG.

Additionally, blood tests can detect hCG before it will reach high enough levels in your urine to test positive on an over the counter test.

Talk to your doctor or visit an urgent care center if you have any questions or concerns about your early pregnancy symptoms before missed period flows.


PlushCare is dedicated to providing you with accurate and trustworthy health information.

Most PlushCare articles are reviewed by M.D.s, Ph.Ds, N.P.s, nutritionists and other healthcare professionals. Click here to learn more and meet some of the professionals behind our blog. The PlushCare blog, or any linked materials are not intended and should not be construed as medical advice, nor is the information a substitute for professional medical expertise or treatment. For more information click here.

Our commitment to you.

PlushCare is dedicated to providing you with accurate and trustworthy health information.

Research from sources you can trust

Medical reviews by field experts

Frequent content updates